Id like the population to be at 500,000,001 to 1,000,000,001 and live on and use only 1/4th of the earths landmass. That way we don't get to the point where we have to become vegetarians and we all don't have to live in Mega Cities as living in cities is believed to increase stress and decrease mental health compared to those living in rural areas.

I second this, although I would be ok with mega cities if it meant consuming less land. Just a lower population living on a smaller fraction of the planet would be ideal.

The eco benefits of a smaller population and less resources/land consumption would be nice, but the main reason I feel this way is, I think it's far easier to give 0.5 billion people a high quality of life (upper middle class American/European or better) compared to 10 billion people. It might even be 100% sustainable at a certain population, too, so all future generations could live and prosper. Basically the closest we'll ever get to a utopia, but I don't see humanity dropping to those populations again without some sort of disaster.

Before reading any replies at all the initial number I said to myself was 500 mil. After reading a few replies I can tell that was a really good guess. Only with a number that low will all our resources be "infinite".

The current fuel consumption will leave us without any crude oil in aprox 40 years from now (with the current discovered oil reserves), lets asume for the sake of it that we still havent found a lot of oil so lets say we have enough for the next 100 years. The problem is what the hell do we do then? A logical thing to do would be to change to electric cars etc, the only problem is if we replaced all petrol cars today and gave them all a lithium battery we would empty 1/3rd of the lithium resources on the planet. Another move you could do is replace all fossil fuel with CO2 neutral fuel that you make from plants that you grow. Once again we have a problem. With the current population of earth it would simply be impossible to grow enough crops for all the vehicles on earth. Currently it would take 1/3rd of the size of USA to provide the people with a year of renewable fuel, as for the entire planet it would most likely take the entire size of America (the continent) but fact is theres almost a billion people living there. Do we ship them to Africa where they still have lots of room?

That is just one type of resource, yes it is one of the more important ones but we also have non salty water which is low on supply. While overpopulation seems like no problem at all in America and Europe fact is that it is going to bite us in the ass at some point or another.

I once wrote a report on this subject and the only solution I could come to back then is if we start enforcing birth like they do in China, only allow 1 kid per familily for the next 3 generations should do it. However that alone would take arround 100 years and by then we will have exhausted a lot of resources on earth. One issue with something like this however is that it would take some sort of world government to make sure every single country on the planet does the same.

Depends entirely on what we can do with our tech, logistics, and governments.

For instance, the countries that have a higher tech level and stronger governments can support quite a few more people than they have now. Some countries that have shitty governments or no governments and generally lower tech levels can't even support their current population without outside help.

We could easily support 20 billion with our current tech level if we had better logistics.

The correct population is whatever our technology can support, for the 18th century we would be overpopulated now, as it is we have an excess of food and plenty of power generation. What bugs me about our population is its all on one planet and wouldn't take much (in the grand scheme of things anyways) to make us extinct.

Proud member of the zero infraction club (lets see how long this can last =)

Obviously, we adapted on a scale superior to any single species on the planet, but we adapt, and force adaptations upon the environment, which can be destructive.

We are the only species on the planet actively and knowingly trying to destroy it. And the majority of us do not care in the least. To me, that makes us the dumbest species on the planet despite our technological "advances" which we are still playing with like little kids with a new toy.

We are using up resources, people who say otherwise are silly. Why? Fish stocks and whales just two of many examples.. Whales have not fully recovered from our mass hunting of them. Fish stocks are low we net so many in the EU and have been advised by many scientists on out right bans of fishing to let stocks recover. This won't happen. We also have a load of trash stretching to the size of texas floating around in the pacific, not to mention deforestation as forest store a lot of co2 and help retain water. So if we can bring those factors to a managble level instead of carrying on as is we should have fewer problems. To survive we need to expand, not just look inward. That means leaving this planet and expanding out. Any species that lives in 1 place will die out, that is a fact. You improve your chances of survival by spreading out so if something bad happens in one area you will be unaffected in another.

As for other resources like metals etc, we have near earth asteroids that are in trojan orbits, meaning they lag a bit behind the earth and are actually not that hard to get to. As someone pointed out earlier they have a lot of minerals and resources we can use from. The other major factor is fossil fuels they are finite, meaning we need alternatives. A good alternative would be if we can get fusion going on a wide scale for power production. There are plenty of helium 3 resources in our solar system. Each of these does require significant technological advances to be made to make the extraction of these resources possible.

As many as we can fit comfortably. Maybe 50 billion? If we run out of resources, we'll get them from somewhere else. Regardless, we just need more humans.

I hope you realize how stupid that statement is. We are running out of resources currently and no we cant just get them from somewhere else. We cant get fish, drinkable water, fossil fuels, plants, hell even atmosphere from somewhere else. Theres too much polution because of over consumption which in turn causes the atmosphere to become thinner and thinner. Think of it as a video game, once you emptied all the resources they are respawning and that takes a very long time (in case of rl we are talking decades).

And how empty some areas are tbh, lots and lots and lots of space in many places...
Just bad planning and people crowding to same cities

Yup, indeed, like arid deserts where to set a reliable water and food source would be more problem then it's worth.
Or... the siberian land and Antarctica, where people can simply go out and freeze on some winter nights, maybe then someone could take them out like those intact mammoths that were found.
Or the oceans, where we get our food source, where setting human shelters would destroy the ecosystem in a place where overfishing already does huge damage.
Have I missed anything?

So no, it's not reliable to have people live on earth in many places, deserts, frozen wastelands or oceans are not places where humans can or should live because it would create more problems then it's worth. Why do you think so few people live in the Sahara and virtually nobody but scientists live in Antarctica? Because of the political situation? NO, it's because those areas are areas where getting any resource would be a pain in the ass.

---------- Post added 2013-01-16 at 09:04 PM ----------

Originally Posted by poser765

I spend a very large part of the day, all day flying over the earth. What I see is LOTS of empty space. I can't even convey with words how empty most of the land mass in the US is. Sure there are some areas that are heavily populated but those are small islands in the sea.

Yes, there is a lot of empty space in the US. Really gives you the chance to... enjoy forests and grow crops and not build cities around volcanoes.

But hey, we should cut all those trees down to make room for more crops to sustain more people, we should get rid of all animals and trees, in the end, they don't benefit us much, do they? Wait... don't they produce our oxygen?

I spend a very large part of the day, all day flying over the earth. What I see is LOTS of empty space. I can't even convey with words how empty most of the land mass in the US is. Sure there are some areas that are heavily populated but those are small islands in the sea.

Sure some of these areas are empty, but how many of these areas are really hospitable for humans to live in?